That looks like polyester cord. That size would have a 500 pound breaking strength. If it is polyester you would have to do a lot to abrade it to breaking.
I live in Iceland and it so happens that I have connections to a company that's one of the biggest in the world in making fishing nets and will be talking to them about making one for me.
I've seen the brewhauler and will get one of them if this doesn't work out, but the fishing net one looks so much better